Locking connector



Jan. 21, 1959 J. HEALY 2,871,456

LOCKING CONNECTOR Filed March 7. 1952 2,871,456 LOCKING CONNECTOR Joseph F. Healy, Westport, Conn., assignor to Harvey Hubbell, Incorporated, Bridgeport, Conn., a corporation of Connecticut Application March 7, 1952, Serial No. 275,400

4 Claims. (Cl. 339-42 This invention relates to an electrical connector comprising a plug member and a receptacle member which when joined may be locked together.

It has for an object to provide a cord connector which may be locked together in such a manner as to prevent inadvertent separation, which would thereby cause a break in the circuit.

It has for a further object to provide a means for making contact between the electrical contacts of the plug and receptacle when the plug is inserted into the receptacle without the plug and receptacle being necessarily locked together, and will maintain this contact when the plug and receptacle are locked. Thus the making and breaking of the circuit occurs when the plug is inserted into the receptacle and removed therefrom, and prevents objectionable arcing between the contacts, which would be damaging to the contacts.

With the foregoing and other objects in view, -I have devised the'construction illustrated in the accompanying drawing forming a part of this specification. It is, however, to be understood the invention is not limited to the nitcd States Patent specific details of construction and arrangement shown,

but may embody various changes and modifications within the scope of the invention.

In the drawing: 1

Fig. l is a longitudinal section of another form of the device showing the plug and receptacle in connected position;

Fig. 2 is a section taken substantially on line 22, Fig. 1;

Fig. 3 is a sectional view taken substantially on line 33 of Fig. 1;

Fig. 4 is a sectional view taken substantially on line 4-4 of Fig. 1;

Fig. 5 is a bottom or inner end view of the plug portion of the device;

Fig. 6 is a top View of device;

Fig. 7 is a detail section through two adjacentcontact blade entrance slots of the receptacle and a blade locking recess between them; and

Fig. 8 is a view of a portion of a contact in the receptacle.

In the form of the device shown in'Figs. 1 to 8, a spring arrangement is used which is adapted for use with a multiple contact plug and receptacle. The plug 34 comprises an insulating body member 32 including an inner reduced extension 33 in which are molded a pluthe receptacle portionof the rality of blade contacts 31. These contacts 31 are molded in the side walls of the extension 33 and anchored therein end wall 38a of the shell by a tubular bushing or sleeve 38b of insulating material. The widened free end portions 41 of the contacts 31 project radially from the extension 33 to correspond with a like number of radially arranged slots 42 providing openings in the end wall of the member 43 for entrance of the contact blades 41 of the cap. Receptacle spring contacts 44 are arranged in the receptacle 43 in a position beneath or inwardly of the slots 42, and are secured to the insulating body member 45 by a suitable means, such as rivets 46 through the insulating body 45 and secured to connectors 47 which are connected to lead wires 48 from the cable 49 by soldering or other suitable means. The insulating body of the receptacle comprises the upper or outer member 57 and the lower or inner member 45 connected together by the screws 59 passing through these members and threaded into the end wall 58a of the metal shell or casing 58, as shown at 59a. The member 57 has a cylindrical side wall 57a enclosing the contacts 44 and other members.

The receptacle 43 comprises a pin 50 molded and anchored at its lower or inner end in the body 46 and extending upwardly to engage a longitudinal hole or recess 51 at the center of the extension 33 on the cap 34 and extending inwardly from the free end of this extension. When the cap 34 is inserted into the receptacle 43 the pin enters this recess to help guide the cap. A spring 52 over the pin 50 and seated in an annular groove 53 in the receptacle body 45 supports a plunger 54 slidable on pin 50 which pushes against the face of the extension 33 in the cap 34. Thus when the cap 34 is joined with the receptacle 43, the extension 33 pushes down on the plunger 54-, compressing the spring 52. At the same time, the widened portions 41 of cap contacts 31 engage the spring contacts 44 of the receptacle 43. These contacts 44 are widened and transversely curved at their upper ends, as shown at 44a in Figs. 2 and.8. Then by a relative turning movement the hooked lugs 55 extending from the widened portions 41 of the contacts 31 are placed into position immediately below the recesses 56 in the insulating member 57 of the receptacle 43. When the pressure between the plug and the cap is released the spring 52 forces the plunger 54 upwardly so that the hooked portions 55 engage within the recesses 56. During the relative turning movement of the plug and receptacle the plug contacts 41 remain in engagement with the widened portions 44a of receptacle contacts 44, thus maintaining the electrical connection between them. It can be seen with this arrangement, as with the arrangement heretofore described, the contacts 31 on the cap 34 engage the spring contacts 44 in the receptacle 43 when the cap is inserted into the receptacle, and maintain this contact during the relative turning movement which locks them together, as heretofore described. To release the contacts the cap 34 is pushed insufiiciently to remove the hooked portions 55 from the recesses 56 and then by a relative turning movement the contacts 31 are placed in position beneath the slots 42 from which they may be withdrawn.

The body members 57 and 45 in the receptacle 43 are encased within a shell 58 and are held within that casing 58 by means of screws 59 through the insulating body members 57 and 45 which screw into tapped holes 60 in by transverse openings 31a into which the molded material enters. The contacts 31 are connected to lead wires 35 from the connecting cable 36 by having the lead wires 35 soldered into holes 37 in the ends of the contacts 31. The body portion 32 with the contacts 31 are held within a casing 38 by means of screws 39 which are screwed into tapped holes 40 in the casing 38. The insulating body member 32 is spaced from the the end of the casing 58. It can readily be seen that this form of the device provides a suitable locking means for locking the plug and the cap together, this form being preferable when it is necessary to employ many contacts.

The central pin 50 serves several purposes. It serves as a sliding guide for the plunger 54 and insures concentricity for both the plunger and plug. It also prevents insertion of certain other types of electrical plugs into the receptacle Patented Jan. 27, 1959}.

which might be damaging, as the inserted plug, for example, would have to have a recess to receive this pin, and it, with plunger 54, makes it more difiicult to tamper with .the device by insertion of foreign articles. When the plug is removed the'spring'52 holds the plunger 54 against the under sideof the upper end wall of body member 57 so that it acts as a closure for the'ent'rance opening 57b to prevent entrance of foreign elements. 7

An important'feature of the'device is that the contact fingers or blade contacts of the plug or cap engage the contacts in the receptacle by the'relative longitudinal movement of the cap and receptacle as these contact fingers are inserted'into the receptacle to thus close" the electric circuit, and this engagement and the electrical connection is maintained in all subsequent relative movements between the cap'and receptacle bothin turning the cap to bring the lugson the blades'into 'alignment'with the locking recesses in th'e'receptacle and subsequent longitudinal movement to seat these lugs in the recesses. 'Th'at vis, the receptacle contacts are of suflicient width at their upper or free end portions to maintain this electrical contact and engagement during the relative turning movements. The same result is secured during the reverse movements to unlock and release the cap. Thus arcing in making and breaking the electrical connection is reduced to a minimum, as the circuit is not made'or 'br'olien during the relative turning movements but is always jr'nade and broken on the relative longitudinal movements between the members, which are quicker movements and thus less liable to cause arcing.

Having thus set forth the nature of my invention, I claim: v

1. In a connector of the character described, a rece ptacle comprising an insulating body including an end'wall having a central entrance opening, a plurality of stationary contacts carried by the body, said end wall provided with a series of openings about the central opening leading to the contacts and a series of inwardly facing recesses on its inner side between and spaced from said openings, a, cap including an insulating body provided with an extension to enter the central opening, a plurality of contact fingers mounted on said extension to enter the other openings to engage the said contacts by "relative longitudinal movement between the cap and receptacle, a central longitudinal pin mounted in the receptacle body, said extension on the cap provided with an opening leading from its free end to receive the pin, a plunger in the receptacle mounted for sliding movement on the pin to and from a position closing said entrance opening, a spring tending to shiftthe plunger towardsaid end wall to the closing position, said fingers provided with laterally extending outwardly facing lugs to seat in said recesses by successive relative longitudinal and turning movements between the cap and receptacle, and said spring also acting to press the plunger against the cap extension to retain the lugs in said recesses.

2. in a connector of the character described,- a receptacle comprising an insulatingbody including an-end wall having a central entrance opening, a plurality of stationary contacts carried by the body, said end wall provided with a series of radial slots extending outwardly from said opening forming blade contact entrance-openings leading to said contacts, a cap including an insulating body provided with anyextension to enter the central opening, a plurality of blade contacts mounted on said extension and extending radially outwardly therefrom in position to enter said slots to engage the receptacle contacts by relative longitudinal movement between the cap and receptacle, and cooperating means on the receptacle body and the cap contacts to lock the cap and receptacle against relative turning movement between them and mounted to'become effectlve and ineffective by successive relative longitudinal and turning movements between the cap and receptacle in opposite directions while the blade contacts are in engagement with the receptacle contacts. I v

3. In a connector of the character describedya receptacle comprising an insulating body including an end wall provided'w'ith avcentral entrance opening, a plurality of stationary contacts carried by said body, said end wall being provided with a series of radial slots about and communicating with said opening forming entrance openings for contact blades of a plug-in cap leading to said 'contacts 'to permit'engagement of the blades with the contacts *by relative longitudinal movement between the cap and receptacle} and said end wall being provided with inwardly facing' 'r'e'ce'sses in its inner surface between and spaced from' said slots-to receive outwardly facing locking 'lu'g's'on'the blade-contacts iOlOClC the cap and receptacle against relative turning movements.

' '4. in a-connector of the character described, a recepi tacle comprising an insulating bodyincluding an end wall provided with a central entrance-opening, a plurality ofstationa-ry contacts carried by said body, said end"'wall' being provided with a series of slots about said opening forming entrance openings 'for' contact blades of a plug-in cap leading to said contacts to'permit engagement of the blades with the contacts by relative longitudinal movement between the'cap and receptacle, said'end wall being'provided with inwardly facing recesses inits inner surface between and spaced from said slots to receive. outwardly facing locking lugs 'on the 7 blade contacts to lock, the' cap and receptacle against relativeturni'ng movements, a longitudinally extending guide pin mounted in the receptacle, a plunger guided forsliding "movement on the pin toward and from the end wall and toward and from a'closing position for said first opening, and spring means tending to shift the plunger to closing position and also to engage an inserted cap to shift it outwardly to retain the lugs in the recesses to lock the plug and receptacle against relative turning movement.

References Cited in the file of this patent UNITED STATES PATENTS 1,509,839 Kuhn Sept. 30, 1924 1,593,985 Nielson July 27, 1926 1,618,939 Marth Feb. 22, 1927 1,669,549 Benjamin May 15,1928 2,027,730 Hirmann Aug. 16, 1933 2,069,238. Fraser Feb. 2, 1937 --2,102;625 Hubbell Dec. 21, 1937 2,152,125 Wulle Mar. 28, 1939 2,181,154 Roper Nov. 28,1939 2,253,593 Warren Aug. 26, 1941 2,340,822: Scott Feb. 1, 1944 2,396,901 Tiffany Mar. 19, 1946 n FOREIGN PATENTS France Jan. 6, 

